Control system



1931- E. F. CARTER 1,819,869

CONTROL SYSTEM Filed Oct. 22 1925 Inventor: Emmett]? Carter H i s Attorney.

Patented Aug. 18, 1931 UNITED STATES PATENT OFFICE- EMMETT I. CARTER, OI SCHENECTADY, NEW YORK, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK CONTROL SYSTEM Application filed October 22, 1925. Serial in. 64,876.

My invention-relates to systems for controlllng'the connections of electric circuits,

and has for its principal object the provision 15 means comprising an energy storage device that is utilized to predetermine the time interval between, opening and closing of an electric valve adapted to control the change in circuit connections.

My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be'pointed out in the appended claims.

Referring to the drawing, thesingle figure thereof shows a control system wherein my invention has. been embodied.

Thisfigure shows a relay device 1 which is provided with a contact member'2 for inter- 30 connecting the conductors 3 and with an op erating coil 4 adapted to be supplied with current from a source 5 through an electric valve 6 comprising a grid ,7 inter osed be: tween an anode 8 and a cathode 9. 11 energy storage device shownas a condenser 10 is connected between the grid 7 and cathode 9. A resistor 11 is connected in shunt to' the condenser 10. The relay 1 is provided also with a contact member 12. Heating current is supplied to the cathode 9 from a source '14. A relay 15 comprising an operating coil 16, a. contact member 17 and retarding means, shown as a dash pot 18, is adapted to be operated in response to current supplied from the source 14 through-the contact member 2 of relay'l. In the closed or upper position of the relay 1, current is supplied to the condenser. 10 from a source 19 through the contact member 12 and a resistor 20. In the open position of the relay 1, the contact member 12 is adapted to cooperate with the contact member 17 of relay 15 for connecting the source 19 directly to the condenser '10.

Throughout the specification and claims, the

valve 6 is described as open when it transmits sufiicient current to operate the relay 1 and as closed when the current transmitted is,

incapable of operating this relay.

The operation of the arrangement will be readily understood if it be assumed that the relays l and 15 are in their illustrated-open positions. Under these conditions, the source 19 is disconnected from the condenser 10, the condenser is discharging at a rate predetermined by the adjustment of the resistor 11 and the negative potential applied to the grid 7 'is gradually decreasing. When this potential has attained a predetermined value, the valve 6opens and the relay 1' is operated to itsclosed position thereby interconnecting conductors 3, producing closure of relay 15 and connecting the condenser to the source 19 through resistor 20.

With these connections-the condenser is charged at a rate determined by the adjustment of resistors 11 and 20 and the potential of grid 7 eventually attains a potential at which the valve 6 is closed. When this occurs, the relay 1 opens and full voltage of the source 19 is appliedto the condenser 10 during .a brief time interval determined by the delay in the operation of the relay 15 which is deenergized by opening of relay 1. The application of full votage to the condenser during the latter part of its charging period is of advantage in that is ensures uniformity 1n the charges applied to the condenser during successive charging intervals. Opening of the relay 15 interrupts the circuit between the source 19 and condenser10 and thesequence of operations previously set forth is repeated. 7 It will be observed that the time interval between opening and closure of the circuit 3 is determined by the retardationlof relay 1 5 and by the rate at which condenser 10 is discharged through resistor 11 and that the time interval between closure and opening of the circuit 3 isdependent on the rate at which the condenser is charged by current supplied through the resistor 20. By suitable adjustment of the resistors 11 and 20 any desired relation may therefore be established between these periods.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the invention is susceptible of being modified to meet the diilerent conditions encountered in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination of an electrical valve comprising a grid interposed between a cathode and anode, an energy storage device connected between said cathode and grid for controlling the conductivity of said valve, a circuit control device connected between said cathode and anode, and means responsive to the operation of said control device for predetermining the rate at which energy is supplied to said storage device.

2. The combination of an electrical valve comprising a grid interposed between a cathenergy to be supplied to said storage device during a difi'erent predetermined time interval, and means for dissipating the energy of said storage device at a predetermined rate. In witness whereof, I have hereunto set my hand this 21st day of October, 1925-.

' EMMETT F. CARTER.

tion of said control device in one direction for causing energy to be suppled to said storage device at one voltage, and means responsive to o eration of said control device in another irection for causing energy to be supplied to said device at a different voltage.

3. The combination of an electrical valve including a grid interposed between a cathode and anode, an energy storage device connected between said cathode and grid for controlling the conductivity of said valve, a control device connected between said cathode and anode, means responsive to operation of said control device in one direction for causing energy to be supplied to said storage means during one predetermined time interval, and means responsive to operation of said control device to another position for causing energy to 'be supplied to said storage device dulring a different predetermined time interva 4. The combination of an electrical valve including a grid interposed between a cathode and anode, an energy storage device connected between said cathode and grid for controlling the conductivity of said valve, a control device connected between said cathode and anode, means responsive to operation of said control device in one direction for causingenergy to be supplied to said storage means during one predetermined time interval, means responsive to operation of said control device to another position for causing 

